Mining Shovel Roller Saddle Block

ABSTRACT

A mining shovel roller saddle block structure has first and second pairs of rollers which roll atop the shovel&#39;s dipper handles. Shafts mounted within the rollers are rotatably supported by block clamps fastened to shelves fixed atop the shovel&#39;s saddle blocks. Drop stops fixed to the shelves between the rollers extend over the dipper handles. Cables coupled between the block clamps and the drop stops retain the structure if it is dislodged by a collision with greenhorn protrusions on the dipper handles.

TECHNICAL FIELD

This disclosure addresses reduction, and expedited repair, of the damage which can result when a mining shovel's dipper handle “greenhorn” protrusions collide with the shovel's saddle blocks.

BACKGROUND

One common type of mining shovel (e.g. the model 4100XPC shovel available from P&H Mining Equipment Inc. of Milwaukee, Wis.) has a boom supported between a pair of saddle blocks. A pair of dipper handles extend longitudinally adjacent to and on either side of the boom. A gear rack on the bottom of each dipper handle engages a pinion mounted on a shaft that extends through the saddle blocks. The mining shovel's bucket is mounted at the forward end of the dipper handles. The shovel operator actuates a mechanism which drives the dipper handles forwardly or rearwardly, relative to the saddle blocks.

So-called “greenhorn” protrusions are provided on the opposed ends of each dipper handle gear rack. The greenhorns protrude outwardly from the dipper handles and act as stops to limit longitudinal movement of the dipper handles relative to the saddle blocks. However, a novice (i.e. “greenhorn”) operator may actuate the dipper handles too quickly, causing the greenhorns to collide at speed with and damage the saddle blocks. The consequential repair operation can cost about $50,000 per saddle block—not including the significant cost implications of lost operation of the mining shovel during the downtime required to make the necessary repairs.

Heavy open gear lube oil (“OGL”) is automatically dispensed onto the dipper handles to lubricate them in the vicinity of the saddle blocks. Each year, approximately sixty-five 5-gallon pails of OGL oil are required to lubricate a typical mining shovel in the vicinity of the saddle blocks. This presents an environmental concern because the oil gradually runs off the mining shovel onto the ground. The OGL run off problem is exacerbated during extreme cold weather.

This disclosure addresses the foregoing problems.

The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

FIG. 1 is a front sectional view of a mining shovel boom, depicting a leftward (as viewed in FIG. 1) roller saddle block structure atop the shovel's leftward dipper handle and a rightward (as viewed in FIG. 1) roller saddle block structure atop the shovel's rightward dipper handle.

FIG. 2 is a top view of the FIG. 1 apparatus.

FIG. 3 is a right side view of the apparatus depicted in FIGS. 1 and 2.

FIG. 4 is a left side view of the leftward roller saddle block structure.

FIG. 5 is a front sectional view of the forward portion of the leftward roller saddle block structure.

FIG. 6 is a right side view of the leftward roller saddle block structure.

FIGS. 7A, 7B and 7C are respectively top, side and front views of a block clamp portion of a roller saddle block structure.

FIGS. 8A and 8B are respectively front and side views of the roller portion of a roller saddle block structure; FIG. 8C being an enlarged view depicting the encircled portion of FIG. 8A.

FIGS. 9A and 9B are respectively front and side views of a roller shaft rotatably mountable within the roller depicted in FIGS. 8A-8C.

FIGS. 10A and 10B are respectively front and side views of a pair of bushings for rotatably mounting the roller shaft depicted in FIGS. 9A-9B within the roller depicted in FIGS. 8A-8C.

FIGS. 11A and 11B are respectively front and side views of a roller end cap for the roller shaft depicted in FIGS. 9A-9B; FIG. 11C being an enlarged view depicting the encircled portion of FIG. 11B; and FIG. 11D being a further enlarged view depicting the encircled portion of FIG. 11C.

FIGS. 12A and 12B are respectively front and side views of a shaft thrust plate for the roller shaft depicted in FIGS. 9A-9B.

FIGS. 13A and 13B are respectively front and side views of a roller thrust plate for the roller shaft depicted in FIGS. 9A-9B.

FIG. 14 is a front view of a shim for the block clamp depicted in FIGS. 7A-7C.

DESCRIPTION

Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

FIGS. 1-3 show mining shovel boom 10 supported between left and right roller saddle blocks 12, 14. Left and right dipper handles 16, 18 extend longitudinally adjacent to and on either side of boom 10. Left and right gear racks 20, 22 on the bottom of dipper handles 16, 18 respectively engage left and right pinions 24, 26 respectively. Pinions 24, 26 are mounted on a shipper shaft (not shown) which extends through roller saddle blocks 12, 14. The mining shovel's bucket (not shown) is mounted at the forward end of dipper handles 16, 18. The shovel operator actuates a mechanism (not shown) to drive dipper handles 16, 18 forwardly or rearwardly relative to roller saddle blocks 12, 14. Mining shovel boom 10; dipper handles 16, 18; gear racks 20, 22; and pinions 24, 26 are standard components of a prior art mining shovel. Roller saddle blocks 12, 14 have been modified in comparison to conventional saddle blocks by removing portions which conventionally overhang dipper handles 16, 18 respectively.

Pairs of outwardly flanged rollers 28, 30 and 32, 34 are rotatably mounted above dipper handles 16, 18 respectively. Specifically, roller 28 is mounted on roller shaft 36 which is rotatably mounted within block clamps 38, 40; roller 30 is mounted on roller shaft 42 which is rotatably mounted within block clamps 44, 46; roller 32 is mounted on roller shaft 48 which is rotatably mounted within block clamps 50, 52; and roller 34 is mounted on roller shaft 54 which is rotatably mounted within block clamps 56, 58.

Each one of block clamps 38, 40, 44 and 46 has a lower portion which is bolted to shelf 60, as best seen in FIGS. 4, 5, 6, 7A, 7B and 7C. Each one of block clamps 38, 40, 44 and 46 also has an upper portion which is bolted to the corresponding lower portion of the block clamp. Similarly, each one of block clamps 50, 52, 56 and 58 has a lower portion which is bolted to shelf 62, as shown in FIGS. 1, 2 and 3. Each one of block clamps 50, 52, 56 and 58 also has an upper portion which is bolted to the corresponding lower portion of the block clamp. The undersides of shelves 60, 62 are welded atop roller saddle blocks 12, 14 respectively.

Drop stop 64 is welded atop shelf 60 between block clamps 38, 40 and 44, 46. As best seen in FIG. 2, drop stop 64 extends transversely across shelf 60 and protrudes above dipper handle 16, between rollers 28, 30. Similarly, drop stop 66 is welded atop shelf 62 between block clamps 50, 52 and 56, 58. As best seen in FIG. 2, drop stop 66 extends transversely across shelf 62 and protrudes above dipper handle 18, between rollers 32, 34.

Lifting eyes 68, 70, 72, 74, 76, 78, 80, 82 are mounted atop the upper portions of block clamps 38, 40, 44, 46, 50, 52, 56 and 58 respectively. As shown in FIG. 4, shackles 69, 73 are coupled to lifting eyes 68, 72 respectively. Cable 85 extends through aperture 84 in drop stop 64. One end of cable 85 is coupled to shackle 69. The opposite end of cable 85 is coupled to shackle 73. A second cable (not shown) is similarly coupled through aperture 86 in drop stop 64 between lifting eyes 70, 74. A third cable (not shown) is similarly coupled through an aperture in drop stop 66 between lifting eyes 76, 80; and a fourth cable (not shown) is similarly coupled through another aperture in drop stop 66 between lifting eyes 78, 82.

FIGS. 8A and 8B depict roller 30 in isolation. An optional lubricant injection passage 88 can be formed in roller 30. Cap 90 is threadably fastened over the injection port end of passage 88 and can be temporarily removed for injection of lubricant into passage 88. Lubricant injected into passage 88 flows through passage 88 to lubricate shaft 42 relative to bushings 92, 94. Instead of (or in addition to) forming passage 88 in roller 30 as shown, another lubricant injection passage (not shown) may be formed in shaft 42. Rollers 28, 32 and 34 are identical to roller 30. Rollers 28, 30, 32, 34 may be formed of an ultra heavy duty, hardened, material such as SAE grade 4140 steel or T-1™ steel. The surfaces of rollers 28, 30 and 32, 34 which contact dipper handles 16, 18 do not require lubrication, thus eliminating the aforementioned OGL environmental problem.

FIGS. 9A and 9B depict roller shaft 42 in isolation. Roller shaft 42 is rotatably supported within roller 30 by bushings 92, 94 (FIGS. 10A, 10B) which are fitted into the opposed ends 96, 98 of aperture 100 which extends longitudinally through roller 30. Roller shafts 36, 48, 54 are identically rotatably supported within rollers 28, 32, 34 respectively.

Roller end cap 104 (best seen in FIGS. 11A and 11B) is bolted over the inward end of roller 30 (as seen in FIG. 2). Identical roller end caps 102, 106, 108 are bolted over the inward ends of rollers 28, 32, 34 respectively. Roller end caps 102, 104, 106, 108 cover the inward ends of shafts 36, 42, 48, 54 respectively. O-ring 110 (FIG. 11D) is fitted within circumferential groove 112 formed in flange 114 of roller end cap 104 to assist in retaining lubricant within roller 42. Similar O-rings (not shown) are provided in the flanges of end caps 102, 106, 108 respectively.

Shaft thrust plate 116 (best seen in FIGS. 12A and 12B) is bolted onto the inward end of shaft 42 as seen in FIG. 5. Identical shaft thrust plates (not shown) are bolted onto the inward ends of shafts 36, 48, 54 respectively.

Roller thrust plate 122 (seen in FIGS. 1, 2, 5 13A and 13B) is fastened (e.g. by shrink fitting) around shaft 42, adjacent outward flanged rim 128 of roller 30. A mechanical seal is coupled between roller thrust plate 122 and rim 128 to assist in retaining lubricant within roller 30. Identical roller thrust plates 118, 124, 126 are similarly fastened and sealed around shafts 36, 48, 54 adjacent outward flanged rims 120, 130, 132 of rollers 28, 32, 34 respectively as seen in FIGS. 1 and 2.

FIG. 14 depicts shim 134 which is sized and shaped for slidable insertion between any of block clamps 38, 40, 44, 46 and shelf 60; or between any of block clamps 50, 52, 56, 58 and shelf 62. A plurality of similarly shaped shims, each having a different thickness dimension, can be inserted (i.e. stacked) between the respective block clamps and shelves, as shown in FIGS. 1-6, 7B and 7C.

In operation, rollers 28, 32 and 30, 34 roll atop dipper handles 16, 18 respectively as the shovel operator controls forward or rearward travel of the dipper handles. The rollers' outward flanged rims 120, 128, 130, 132 respectively contact the dipper handles' outward sides (i.e. the left side of dipper handle 16 and the right side of dipper handle 18 as viewed in FIGS. 1 and 2) to maintain alignment of the rollers atop the dipper handles. If a novice (i.e. “greenhorn”) operator actuates dipper handles 16, 18 too quickly, the greenhorn protrusions (not shown) on the opposed ends of each dipper handle may collide at speed with rollers 28, 32 or 30, 34 (depending on the dipper handles' direction of travel). Such collision applies an upwardly directed force to the underside of rollers 28, 32 or 30, 34. The collision force is transmitted through the roller shafts and block clamps, and may break bolts 136 which fasten the block clamps to shelves 60, 62 respectively. If bolts 136 break, then the roller saddle block structure (i.e. the roller, roller shaft and block clamps) would ordinarily fall away from the mining shovel, potentially damaging other portions of the mining shovel and/or nearby equipment; and/or potentially injuring nearby personnel. However, drop stops 64, 66 (to which the block clamps are cabled and shackled as aforesaid) prevent the roller saddle block structure from falling away from the mining shovel. For example, with reference to FIGS. 1, 2, 4 and 5; if all of bolts 136 associated with either or both of the roller saddle block structures formed by rollers 28, 30, roller shafts 36, 42, and block clamps 38, 40, 44, 46 break; then either or both of those roller saddle block structures may become separated from shelf 60. However, cables (e.g. cable 85) are shackled at both ends to the respective roller saddle block structures and are retained by passage of the cables through drop stop 64, thus preventing either roller saddle block structure from falling away from the mining shovel.

It is relatively simple to use a crane to remove a damaged roller saddle block structure and to manouevre a replacement structure into position to replace the damaged structure. The damaged structure can be transported to a shop for repair (e.g. replacement of broken bolts, or repairing possible damage to the rollers).

Conventional saddle blocks require periodic maintenance to accommodate normal wear. During such maintenance operations, the conventional saddle block's overhang structure (i.e. the saddle block portion which conventionally overhangs the dipper handles) is unbolted and removed with the aid of a crane, shims are inserted (or removed) to offset accumulated wear, and the overhang structure is then replaced and bolted back down atop the shims. In contrast, a plurality of shims 134, each having a different thickness, are pre-installed (i.e. stacked) between each block clamp and the shelf to which the block clamp is bolted, as seen in FIGS. 1-6, 7B and 7C. In order to accommodate wear of rollers 28, 30, 32, 34 a workman need only loosen bolts 136, slidably remove an appropriate one of pre-installed shims 134, then re-tighten bolts 136. No crane is required to perform this shim adjustment operation.

While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. For example, roller saddle block structures can be fabricated and installed at the factory during construction of a new mining shovel. Alternatively, a mining shovel's conventional saddle blocks which have been damaged as aforesaid can be reconfigured as roller saddle block structures as explained above.

As another example, instead of extending a single cable through a drop stop and shackling the cable's opposed ends to roller saddle block structures on opposite sides of the drop stop, one could provide two cables. One end of each cable could be connected to the drop stop and the opposed end of each cable could be connected to one of the roller saddle block structures.

It is intended that the scope of the claims should not be limited by the embodiments set forth above, but should be given the broadest interpretation consistent with the description as a whole.

DRAWING REFERENCE NUMERALS

-   10 mining shovel boom -   12 saddle block -   14 saddle block -   16 dipper handle -   18 dipper handle -   20 gear rack -   22 gear rack -   24 pinion -   26 pinion -   28 roller -   30 roller -   32 roller -   34 roller -   36 roller shaft -   38 block clamp -   40 block clamp -   42 roller shaft -   44 block clamp -   46 block clamp -   48 roller shaft -   50 block clamp -   52 block clamp -   54 roller shaft -   56 block clamp -   58 block clamp -   60 shelf -   62 shelf -   64 drop stop -   66 drop stop -   68 lifting eye -   69 shackle -   70 lifting eye -   72 lifting eye -   73 shackle -   74 lifting eye -   76 lifting eye -   78 lifting eye -   80 lifting eye -   82 lifting eye -   84 aperture -   85 cable -   86 aperture -   88 lubricant injection passage (in roller 28) -   90 cap -   92 bushing -   94 bushing -   96 open end of aperture 100 -   98 opposed open end of aperture 100 -   100 longitudinal aperture (in roller 28) -   102 roller end cap -   104 roller end cap -   106 roller end cap -   108 roller end cap -   110 O-ring -   112 circumferential groove (in flange 114) -   114 flange (of roller end cap 102) -   116 shaft thrust plate -   118 roller thrust plate -   120 flanged rim (of roller 28) -   122 roller thrust plate -   124 roller thrust plate -   126 roller thrust plate -   128 flanged rim (of roller 30) -   130 flanged rim (of roller 32) -   132 flanged rim (of roller 34) -   134 shim -   136 bolt -   138 bolt -   140 -   142 -   144 

What is claimed is:
 1. A roller saddle block structure for a mining shovel, the structure comprising: first and second rollers rotatably mountable atop a first dipper handle of the mining shovel; third and fourth rollers rotatably mountable atop a second dipper handle of the mining shovel; a first shaft rotatably mounted within the first roller; a second shaft rotatably mounted within the second roller; a third shaft rotatably mounted within the third roller; a fourth shaft rotatably mounted within the fourth roller; a first block clamp rotatably supporting the first shaft, the first block clamp fastened to a first shelf fixable atop a first saddle block of the mining shovel; a second block clamp rotatably supporting the second shaft, the second block clamp fastened to the first shelf; a third block clamp rotatably supporting the third shaft, the third block clamp fastened to a second shelf fixable atop a second saddle block of the mining shovel; and a fourth block clamp rotatably supporting the fourth shaft, the fourth block clamp fastened to the second shelf.
 2. A roller saddle block structure as defined in claim 1, further comprising: a first drop stop fixed to the first shelf between the first and second rollers to extend over the first dipper handle; and a second drop stop fixed to the second shelf between the third and fourth rollers to extend over the second dipper handle.
 3. A roller saddle block structure as defined in claim 2, further comprising: a first cable coupled between the first block clamp and the first drop stop; a second cable coupled between the second block clamp and the first drop stop; a third cable coupled between the third block clamp and the second drop stop; and a fourth cable coupled between the fourth block clamp and the second drop stop.
 4. A roller saddle block structure as defined in claim 2, further comprising: a first cable coupled through the first drop stop between the first block clamp and the second block clamp; a second cable coupled through the second drop stop between the third block clamp and the fourth block clamp.
 5. A roller saddle block structure as defined in claim 2, further comprising: a fifth block clamp rotatably supporting the first shaft, the fifth block clamp fastened to the first shelf; a sixth block clamp rotatably supporting the second shaft, the sixth block clamp fastened to the first shelf; a seventh block clamp rotatably supporting the third shaft, the seventh block clamp fastened to the second shelf; and an eighth block clamp rotatably supporting the fourth shaft, the eighth block clamp fastened to the second shelf.
 6. A roller saddle block structure as defined in claim 5, further comprising: a first cable coupled between the first block clamp and the first drop stop; a second cable coupled between the second block clamp and the first drop stop; a third cable coupled between the third block clamp and the second drop stop; a fourth cable coupled between the fourth block clamp and the second drop stop a fifth cable coupled between the fifth block clamp and the first drop stop; a sixth cable coupled between the sixth block clamp and the first drop stop; a seventh cable coupled between the seventh block clamp and the second drop stop; and an eighth cable coupled between the eighth block clamp and the second drop stop.
 7. A roller saddle block structure as defined in claim 5, further comprising: a first cable coupled through the first drop stop between the first block clamp and the second block clamp; a second cable coupled through the second drop stop between the third block clamp and the fourth block clamp; a third cable coupled through the first drop stop between the fifth block clamp and the sixth block clamp; and a fourth cable coupled through the second drop stop between the seventh block clamp and the eighth block clamp.
 8. A roller saddle block structure as defined in claim 1, further comprising: a flanged rim on the first roller for contacting an outward side of the first dipper handle; a flanged rim on the second roller for contacting the outward side of the first dipper handle; a flanged rim on the third roller for contacting an outward side of the second dipper handle; and a flanged rim on the fourth roller for contacting the outward side of the second dipper handle.
 9. A method of reducing damage caused by collision of protrusions on a mining shovel's dipper handles with saddle blocks supporting the mining shovel's boom, the method comprising: rotatably supporting a first roller in a first support structure bolted to a first one of the saddle blocks for rotation of the first roller on a first one of the dipper handles; rotatably supporting a second roller in a second support structure bolted to the first one of the saddle blocks for rotation of the second roller on the first one of the dipper handles; rotatably supporting a third roller in a third support structure bolted to a second one of the saddle blocks for rotation of the third roller on a second one of the dipper handles; rotatably supporting a fourth roller in a fourth support structure bolted to the second one of the saddle blocks for rotation of the fourth roller on the second one of the dipper handles; coupling a first end of a first cable to the first support structure, extending the first cable through a first stop fixed to the first one of the saddle blocks and coupling a second end of the first cable to the second support structure; and coupling a first end of a second cable to the third support structure, extending the second cable through a second stop fixed to the second one of the saddle blocks and coupling a second end of the second cable to the fourth support structure. 